Safety device for detecting water level in a water tight chamber of an amphibian bulldozer

ABSTRACT

A safety device for detecting water level in a water tight chamber of a radio controlled amphibian bulldozer which has means for detecting the level of leaked water in. A water tight chamber, an electric drain pump is driven by the operation of said means when the water level in the water tight chamber reaches. A predetermined level, a drain pipe connected to the pump drains water in the water tight chamber, and means projected over water surface for warning when the leaking flow rate of water into the chamber exceeds the capacity of the drain pump the warning means may be a lamp or radio transmitting antenna.

States Patent .[191 Kobayashi t [111 3,811,793 [451 May 21, 1974 1 i SAFETY DEVICE FOR DETECTING WATER LEVEL IN A WATER TIGHT CHAMBER OF AN AMPHIBIAN BULLDOZER [75] inventor: Hideyoshi Kobayashi, Osaka, Japan [73] Assignee: Kabushiki Kaisha Komatsu Seisakusho, Tokyo, Japan [22] Filed: June 15,1972 [21] Appl. No.: 263,246

[30] Foreign -Application Priority Data 3,164,095 1/1965 Williams 417/40 2,924,234- 2/1960 Wilson ..4l7/40X 3,279,380 10/1966 Clark ..4l7/40 Primary Emrnitier-C. J. Husar Assistant Examiner-Leonard Smith Attorney, Agent, or FirmArmstrong., Nikaido & Wegner 571 ABST ACT A safety device for detecting water level in a water tight chamber of a radio controlled amphibian bull- I dozer which has means for detecting the level of leaked water in. A water tight chamber, an electric drain pump is driven by the operation of said means when the water level in the water tight chamber reaches. A predetermined level, a drain pipe'connected to the pump drains water in the water tight chamber, and means projected over water surface for warning when the leaking flow rate of water into the chamber exceeds the capacity of the drain pump the warning means may be a lamp or radio transmitting antenna.

3 Claims, 4 Drawing Figures WARNING DEVICE ar- "'1 i R N2 PATENTEDHAYZI I974 sum 2 BF 3 FIG.2

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WARNING DEVICE El pacity of the drain pump.

SAFETY DEVICE FOR DETECTING WATER LEVEL INA WATER TIGHT CHAMBER OFA AMPHIBIAN BULLDOZER BACKGROUND OF THE INVENTION This invention relates to an amphibian bulldozer, and more particularly to a safety device for the water level in a water tight chamber of an amphibian bulldozer:

In the prior art, there are no bulldozers which can be operated under water which are controlled by means of radio from land and which have a water tight engine room of the type used in a ship.

I SUMMARY OF THE PRESENT INVENTION It'is an-object of the present invention to provide a safety device'for the water level in a water tight chamber of an amphibian bulldozer when water leaks into the chamber which could be an engine room.

It is another object of thepresent invention to provide a safety device for detecting the water level in a water tight chamber of an amphibian bulldozer which maintains its operation when the leaking water flow rate is within the capacity of a drain pump.

It is a further object of the present invention to provide a safety device for detecting the water level in a water tight chamber of an amphibian bulldozer which warns when the leaking water flow rate exceeds, the ca According to one aspect of the present invention, there is provided a safety device for detecting the water level in a water tight chamber of'a radio controlled am ,phibian bulldozer which comprises means for detecting the level of leaked water in a water tight chamber. An electric drain pump is driven by the operation of said means when the water level .in the water tight chamber reaches a predetermined level. A drain pipe is connected to the pump for draining water in the water tight chamber, and means projected over water surface to warn when the leaking flow rate of water into the chamber exceeds the capacity of the drain pump. The warning means could for example be a warning lamp or radio transmitter. Thus, the bulldozer operated under water maintains its operation when the leaking water flow rate is within the capacity of the drain pump, and it produces a warning when the leaking water flow rate exceeds the capacity of the drain pump.

1 These and other objects, features and advantagesof the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION or THE DRAWINGS reed switch used in the device of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is nowmade to the drawings, particularly to FIG. 1, which shows one embodiment of a radio controlled amphibian bulldozer with a safety device for detecting the water level in a water tight chamber constructed according to the present invention.

Reference numeral 1 illustrates a water tight engine room of the amphibian bulldozer, and 2 and 3 are ventilating tubes. A device 4 for detecting water level is provided at the lower portion of the water tight engine room 1. r

Referring now to FIG. 2, a float or level switch which is used for the device 4 for detecting water level. This level is shown switch 4 has a float 5, in which an annular magnet. 6 is fixed, and a stem 7, in which a reed switch 8 is sealingly fixed. This stem 7 vertically stands in the water tight chamber 1, and the float 5 slidably moves. along the stem 7.

In operation of thus constructed level switch 4, when a the water level is raised in the float 5 of the level switch 4, the reed switch 8 within the stem 7 is affected by strong magnetic field of the annular magnet 6 provided in the float 5. Thus the contact 9 of the reed switch 8 turns ON so as to provide an output signal therefrom. The water which leaks through the upper air intake port 2, exhaust port 3 and the respective sealing sur* faces of the water tight chamber 1 due to any cause is accumulated on the lower portion of the water tight chamber 1. This water level is automatically checked by the device 4 for detecting the water level, and when the leaked water reaches a predetermined level in the I water tight chamber 1, the drain pump 10 is operated thereby so as to drain the water tight chamber 1 through a drain tube 11 passing through the exhaust poIt 3 of the water tight chamber 1.

Reference is now made to FIG. 3, which shows one embodiment of the safety device of this invention as an ple, three level switches S1, S2 and S3.

In operation, when water leaks into the engine water tight chamber 1 so that the water level reaches level A in FIG. 3, the level switch S1 turns ON. Then, when the water level in the chamber 1 is raised to the level B, the level switch S2 turns ON. Therefore, the coil R in a relay 12 is energized so that both the switches S4 and S5 turns ON at the same time, and accordingly the drain pump 10 connected to the circuit of the switch S5 is energized to drain the water tight chamber 1. When the drain pump 10 starts to operate so that the water level in the water tightchamber 1 is lowered below the level B, the level switch -S2 tums OFF. But since the switch S4, which is a self-holding circuit of the coil R, is in still closed, the coil R of the relay 12 remains energized. Therefore, the switch S5 also remained closed, and accordingly the drain pump 10 maintains operation so as to continue to drain the water tightchamber 1. Further, when the water level is lowered below the level A, the level switch S1 turns OFF. Then, the energizing current of the coil R is shut off, with the result that both the switches S4l'and S5 are opened simultaneously, and accordingly the electric power from a power supply 13 to the drain pump 10 is shut off. This results in the de-energization of the drain pump 10. As

above, if the water level is still raised even if the drain pump is operating to drain the water tight chamber 1, that is, the leaking water flow rate into the water tight chamber 1 exceeds the capacity of the drain pump, the water level is further raised over the level C so that the level switch S3 turns ON. This results in a signal is applied to the warning device 14. The warning device 14 may be of a lamp or. horn projecting upwardly higher than the water surface 15 over the under water bulldozer, or a transmitter for warning of a dangerous state to the land including the antenna, as shown in FIG. 1. When such warning signal is provided, the bulldozer must immediately be floated to be carried onto land. A plurality of lamps may be used as indicators of the following conditions dangerous water level in the water tight chamber by red lamp, the inclination of the vehicle over 30 by blue lamp, the overheating of the engine or torque converter, and/or excessively low oil pressure of the engine by yellow lamp.

Referring now to FIG. 4, which shows one example of a reed switch used in the safety device of this invention, the reed switch 8 may be contained in one plastic case 17 so constructed that when a magnet 19 contained in another plastic case 18 approaches, the contact comes together in a snap action. If the absorbing force produced by the magnetic field of the magnet 19 exceeds the tension of the spring (not shown) and the contacts remains closed, but when the magnet 19 moves in the reverse direction, the contacts 20 are opened. I

it should be understood from the foregoing description that since the device of this invention is thus constructed, the safety device of this invention may maintain safely the operation of the bulldozer under water if the leaking water flow rate is below the capacity of the drain pump even if water leaks into the water tight engine room due to any cause. At the same time the bulldozer may be immediately carried onto land when the water level in the water tight engine room becomes dangerous if the leaking water flow rate exceeds the capacity of the drain pump so as to protect the bulldozer from damage.

I claim:

1. A safety device for detecting the water level ina watertight engine chamber of an amphibian bulldozer comprising lowermost, intermediate and uppermost level switches disposed in the watertight engine chamber, each switch including a float, an annular magnet, a stem, and a reed switch sealingly fixed in such a manner that said float slidably moves vertically along said stem in the watertight engine chamber; said reed switch having a normally open contact which is closed by the magnet positioned within the float and concentric with said stem when water level reaches a predetermined level corresponding to the level of each reed switch; an electric power supply; an electrically driven drain pump; a suction pipe connected to said drain pump; a drain pipe connected to said drain pump for draining water from said watertight chamber; warning means for warning when the leaking flow rate of water into the watertight engine chamber exceeds the capacity of said drain pump; and a relay consisting of a coil and two normally open contacts which are closed when the coil is energized for self-holding the energization of the coil after the coil is energized and for energizing said drain pump; wherein said lowermost level switch is electrically connected between said power supply and contacts of said relay for energizing one of the contacts of said relay when the water level in the watertight engine chamber rises above a predetermined lowermost level; wherein said intermediate level switch is electrically connected between said power supply and the other of the contacts of said relay for energizing the coil of said relay when the water level in the watertight engine chamber rises above an intermediate level to close both the contacts of the relay thereby energizing said drain pump and self-holding the energization of said coil even though the water level in the watertight engine chamber drops below the intermediate level; and wherein said uppermost level switch is electrically connected between said power supply and said warning means for warning that the leaking flow rate of water into the watertight chamber exceeds the capacity of said drain pump when the water level is above an uppermost predetermined level.

2. A safety device as set forth in claim 1, wherein said warning means is a radio transmitter.

3. A safety device as set forth in claim 1, wherein said warning means is a lamp. 

1. A safety device for detecting the water level in a watertight engine chamber of an amphibian bulldozer comprising lowermost, intermediate and uppermost level switches disposed in the watertight engine chamber, each switch including a float, an annular magnet, a stem, and a reed switch sealingly fixed in such a manner that said float slidably moves vertically along said stem in the watertight engine chamber; said reed switch having a normally open contact which is closed by the magnet positioned within the float and concentric with said stem when water level reaches a predetermined level corresponding to the level of each reed switch; an electric power supply; an electrically driven drain pump; a suction pipe connected to said drain pump; a drain pipe connected to said drain pump for draining water from said watertight chamber; warning means for warning when the leaking flow rate of water into the watertight engine chamber exceeds the capacity of said drain pump; and a relay consisting of a coil and two normally open contacts which are closed when the coil is energized for self-holding the energization of the coil after the coil is energized and for energizing said drain pump; wherein said lowermost level switch is electrically connected between said power supply and contacts of said relay for energizing one of the contacts of said relay when the water level in the watertight engine chamber rises above a predetermined lowermost level; wherein said intermediate level switch is electrically connected between said power supply and the other of the contacts of said relay for energizing the coil of said relay when the water level in the watertight engine chamber rises above an intermediate level to close both the contacts of the relay thereby energizing said drain pump and self-holding the energization of said coil even though the water level in the watertight engine chamber drops below the intermediate level; and wherein said uppermost level switch is electrically connected between said power supply and said warning means for warning that the leaking flow rate of water inTo the watertight chamber exceeds the capacity of said drain pump when the water level is above an uppermost predetermined level.
 2. A safety device as set forth in claim 1, wherein said warning means is a radio transmitter.
 3. A safety device as set forth in claim 1, wherein said warning means is a lamp. 